This is a model F1 steering wheel. It isn't designed for simulator use just for display and to paint and make look good. 

Change to any size. Change the size to what you want, (THE BIGGER THE BETTER) when you slice it as smaller size may not print correctly. No assemble required. Use low infill density e.g. 10. Use supports because of thin elements and details at the flappy paddles. 0.2mm resolution. Use supports and rafts.